Koenig, 62, of Smyrna, Ga., said many in her family had battled depression and she had personally struggled with it for many years. Worse, various combinations of anti-depressant medications didn't provide her with relief.

"It was hard to find fun and pleasure in life," she said. "I felt like I was living in a black hole and couldn't get out."

Today, however, she said she is getting relief -- and it comes in the form of tiny, current-emitting scalp electrodes that a new study suggests may offer promise in the treatment of depression.

In the study, which was released Wednesday in the Journal of the American Medical Association, researchers in Brazil tested a technique known as transcranial direct current stimulation, or tDCS for short. They tested the approach on 120 patients with moderate to severe depression who were divided into four groups. Some received the scalp-shocking treatments along with the depression drug sertraline. Others received tDCS and a fake version of the drug. The remaining two groups received a fake placebo version of the head-zapping technique with or without the drug.

After six weeks, the group that got both tDCS and sertraline had a greater and more rapid improvement in their depression compared to the other groups.

As for Koenig, her experience with tDCS came only when she was near her wit's end. She sought out the services of Dr. James Fugedy, head of the Brain Stimulation Clinic in Atlanta, Ga. For the past seven years, Fugedy has been treating depressed patients with the technique on an off-label basis.

For most people, the thought of applying electricity to the brain conjures up images of Frankenstein or Jack Nicholson in that final scene of "One Flew over the Cuckoo's Nest."

This technique, however, simply sends small currents to change the way that neurons in the brain send their signals. Specifically, two pads containing electrodes soaked in salt water are placed directly onto the scalp, where they deliver a low, constant electrical current. The position of the electrodes can vary depending on the area in the brain that is targeted. The electrical current alters the circuitry of brain neurons, either activating or suppressing them. After about 20 to 30 minutes, the current is turned off.

The approach is far from unprecedented; tDCS has been used by the military to improve training efficiency of snipers and drone pilots. More recently, it has generated noticeable buzz in the science world as potential treatment for a variety of disorders.

"This is the type of study that shows there may be something clinically meaningful in this treatment," says Dr. Pascual-Leone, director of the Berenson-Allen Center for Noninvasive Brain Stimulation and professor of Neurology at Harvard Medical School, who had previously worked with one of the researchers on the current study.

Pascual-Leone says that tDCS has actually been tested for depression for several decades. More recently, the technique has benefited from technological advances, and researchers like Pascual-Leone are saying that it could be a more favorable, better-tolerated technique for treatment of depression than drugs or electroconvulsive therapy. Late stage clinical trials are currently in the works for use of tDCS for depression.

In fact, the technique is also being explored for treatment of other neuropsychiatric disorders like stroke, Parkinson's disease, seizure disorders and schizophrenia. Dr. Joshua Berman, director of the Program in Brain Stimulation at Columbia Psychiatry, studies tDCS for treatment of hallucinations and chronic pain.

"When you give a medication, it goes everywhere in brain," Berman said. "But with techniques like tDCS, you can identify neuronal circuits that aren't functioning the way you want."

According to Berman, this is why tDCS is being explored as a treatment in various fields.

"You can vary this technique to target different circuits in the brain, depending on the illness," he said.

However, experts caution that more questions need to be answered before tDCS can be used clinically -- and especially at home, as some advocates have suggested.

"The study supports need for a multicenter study to look at duration of benefits and frequency of treatment," Pascuale-Leone said. "Even though side effects are benign, we still don't know about the long-term side effects that can happen after years of treatment with tDCS."

For now, staunch tDCS supporters like Fugedy -- and his patient, Koeing -- plan to stick to its off-label use.

"The most robust response I've seen is with depression," Fugedy said. "I see it, and I believe in it."

Koeing agreed, reporting that after using tDCS twice a week for the past four months, she has noted an "incredible improvement" in her mood.